Adrenocortical hormone exhibits excellent efficacy in many diseases of the skin such as eczema/dermatitis represented by acute or chronic eczema, contact dermatitis, atopic dermatitis, etc., prurigo, e.g. strophulus and urticaria, cutaneous pruritus, psoriasis, etc. and as such has been widely used in clinical practice.
While adrenocortical hormone has very useful pharmacologic efficacy as aforesaid, long-term use of this hormone causes systemic side effects such as suppression of pituitary adrenocortical function even if it is externally used, not to speak of local skin infections and skin symptoms such as acne characteristic of this hormone. Therefore, for securing safety, the hormone is preferably used at a concentration as low as possible. However, any therapy with a topical preparation containing this hormone at such a low concentration cannot insure a sufficient therapeutic effect in such refractory diseases. To enhance the percutaneous absorption of adrenocortical hormone, it has been proposed to use this hormone in a topical therapeutic system containing a percutaneous absorption promoting agent such as urea, propylene glycol, etc. Another approach to this goal is the use of a therapeutic tape which takes advantage of the so-called occlusive dressing technique (ODT), such as Drenison Tape (Dainippon Pharmaceutical Co., Ltd., Japan). However, many problems such as skin irritation, inconvenience in use and so on remain to be solved. Under the circumstances, the advent of a topical therapeutic preparation which would be safe and easy to use has been keenly awaited. The inventor of the present invention explored the possibility of insuring a sufficient therapeutic effect with a topical preparation containing a reduced concentration of adrenocortical hormone and found that when hyaluronic acid is incorporated in a topical therapeutic composition containing adrenocortical hormone in such a reduced concentration, a therapeutic effect comparable to or even surpassing the effect obtainable with the conventional topical preparation containing the usual clinical dose of this hormone can be obtained. The present invention is predicated on the above finding.